An appeal for dashcam footage has been made after four people were taken to hospital following a crash on the A47 on Thursday evening.
Emergency services were called to a collision between a black VW and a white Hyundai on the eastbound carriageway near Acle, at The Windle junction, just before 5.30pm.
Three ambulances, three operations managers and the East Anglian Air Ambulance were sent to the scene.
Part of the road was closed to traffic as emergency services dealt with the incident.
Norfolk Fire and Rescue Service were also in attendance.
Crews from Acle, Carrow and Sprowston made the scene safe.
Four people were later taken to hospital, with three going to the James Paget Hospital and one to the Norfolk and Norwich University Hospital.
Police are looking for anyone with dashcam footage or who witnessed the manner of the driving of the white Hyundai.
The vehicle travelled Yarmouth-bound for a short distance before going Norwich-bound on the carriageway.
The vehicle then travelled on the B1140 Acle Road towards Lingwood.
A man in his 30s was later arrested for dangerous driving and failing to stop at the scene and has since been released under investigation.
Enquiries are ongoing.
Anyone with information should contact PC Mike Stolworthy at Norfolk Police on 101 quoting reference 36/31366/22.
For up-to-date information about the county's roads, visit our LIVE Norfolk traffic map.
Join our Norfolk Travel Information group on Facebook for all the latest traffic news in Norfolk.
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